4D

4D meaning four dimensions is an important idea in geometry. Three-dimension space (3D) has length, depth and height. The fourth dimension is in relation to that three dimensions like a vertical dimension.

In some branches of physics time is considered as a fourth dimension but in real time people are not allowed to perceive it and it is used for modeling physical and social causes.

In mathematics, four-dimension space is an abstract concept which has been studied by mathematics and philosophers for many years. Mathematicians who studied four-dimension space in the 19th century include Möbius, Schläfi, Bernhard Riemann, and Charles Howard Hinton.